Phase II studies are therapeutic investigations of new agents that have finished Phase 1 testing (I.E. clinical toxicology and pharmacology studies). Completed negative Phase II trials have been done with AMSA in oat cell carcinoma of the lung. Trials are currently underway with intravenous 6-thioguanine in colorectal carcinoma; AMSA in malignant melanoma and Methy-G in renal and GU tumors and esophageal cracinoma; and Neocarzinostatin plus VP16-213 in hepatocellular carcinoma.